Anybody who has been seriously engaged in scientific work of any kind realizes that over the entrance to the gates of the temple of science are written the words: Ye must have faith. It is a quality which the scientist cannot dispense with.

I am quite aware that we have just now lightheartedly expelled in imagination many excellent men who are largely, perhaps chiefly, responsible for the buildings of the temple of science; and in many cases our angel would find it a pretty ticklish job to decide. But of one thing I feel sure: if the types we have just expelled were the only types there were, the temple would never have come to be, any more than a forest can grow which consists of nothing but creepers. For these people any sphere of human activity will do, if it comes to a point; whether they become engineers, officers, tradesmen, or scientists depends on circumstances.

If the God of revelation is most appropriately worshipped in the temple of religion, the God of nature may be equally honored in the temple of science. Even from its lofty minarets the philosopher may summon the faithful to prayer, and the priest and sage exchange altars without the compromise of faith or knowledge.

In the temple of science are many mansions, and various indeed are they that dwell therein and the motives that have led them thither. Many take to science out of a joyful sense of superior intellectual power; science is their own special sport to which they look for vivid experience and the satisfaction of ambition; many others are to be found in the temple who have offered the products of their brains on this altar for purely utilitarian purposes. Were an angel of the Lord to come and drive all the people belonging to these two categories out of the temple, the assemblage would be seriously depleted, but there would still be some men, of both present and past times, left inside. Our Planck is one of them, and that is why we love him.

Philosophy dwells aloft in the Temple of Science, the divinity of its inmost shrine; her dictates descend among men, but she herself descends not : whoso would behold her must climb with long and laborious effort, nay, still linger in the forecourt, till manifold trial have proved him worthy of admission into the interior solemnities.

Science, the partisan of no country, but the beneficent patroness of all, has liberally opened a temple where all may meet. Her influence on the mind, like the sun on the chilled earth, has long been preparing it for higher cultivation and further improvement. The philosopher of one country sees not an enemy in the philosopher of another; he takes his seat in the temple of science, and asks not who sits beside him.

In Letter to the Abbι Reynal, on the 'Affairs of North America in which the Mistakes in the Abbιs Account of the Revolution of America are Corrected and Cleared Up', collected in The Works of Thomas Paine (1797), Vol. 1, 295. Originally published in the Pennsylvania magazine (1775).

In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion.
(1987) -- Carl Sagan